1. Field of the Invention
The invention relates generally to the field of rakes and specifically to the field of self-cleaning rakes.
2. Description of the Related Art
Yard and garden rakes have been in use for many decades. Some of the first rakes to be patented date back to the 1800s. A common problem encountered throughout the history of the rake is that leaves and other yard debris continuously become trapped in the tines of the rake during use. This has led to many designs for clearing the tines during the raking process, to thereby speed up the removal of debris. The designs fall mainly into three categories which are described below. In addition, most of the designs include a cleaner handle located along the rake handle that is connected to some sort of actuating rod or cable that actuates the cleaning mechanism at the rake tines.
The first category of designs includes rotating or pivoting cleaning bars or tines. These designs mainly utilize a pivot joint along the row of tines about which a cleaning rack rotates. The tines are partially surrounded by channels in the cleaning rack. As the cleaner handle is moved, the cleaning rack, which is mounted to the pivot joint, rotates about the pivot so that the channels rotate along a path that leads them along some or all of the length of the tines, thereby removing entrapped debris. In an alternative design, the tines are mounted on the pivot joint and when the cleaner handle is actuated the tines rotate to a flat position in line with the handle and are retracted through a cleaning rack. The pivot joint required by this type of design is complicated and somewhat delicate, leading to increased risk of failure of the cleaning mechanism.
The second type of design involves the movement of a support/cleaning bar along the length of the tines. In this type of design, the tines are retracted through a cleaning bar that provides support to the tines. In variations of this design, the cleaning bar is moved along the length of tines to remove entrapped debris. The cleaning bar of these designs acts as a support bar at or near the top of the tines and moves along the length of the tines. The tines of these designs are typically long and flexible, typical of leaf rakes. As the tines and cleaning bar move in relation to each other, the tines are pulled inward by the narrower cleaning bar. The movement inward, or closer together, of the tines can actually increase the binding force on debris caught between the tines and therefore lead to a failure of the cleaning process as the debris binds the cleaning bar and slows or stops it's progress. Additionally, the requirement of these designs, that the cleaning bar travel the length of the tines, requires either a long motion of the cleaning handle or complex linkages to amplify a slight motion of the cleaning handle into longer motion of the cleaning bar. Both of these options are undesirable. The cleaning motion should be short and easy and the linkage should be simple in order to minimize cost and limit the possibility of failure.
The third type of design involves mechanisms that slide a cleaning bar along a relatively short pathway to clean the tines through use of components that only slide along various parts of the rake. However, the rakes falling into this category are either only of the type that can be used for raking dirt or they include actuation components that are exposed and can become damaged or fouled.
From the above, it is apparent that there is a need for a self-cleaning rake that can be used for gathering lawn debris and utilizes a relatively short cleaning stroke by the user. There is a further need for a self-cleaning rake with a simple yet sturdy design that is inexpensive to manufacture and provides reliable performance while minimizing maintenance by the user.